Current hearing aid fitting systems and methods are generally complex, relying on specialized instruments for operation by hearing professionals in clinical settings. For example, a typical fitting system may include an audiometer for conducting a hearing evaluation, a software program for computing prescriptive formulae and corresponding fitting parameters, a hearing aid programming instrument to program the computed fitting parameters, a real ear measurement (REM) instrument for in-situ evaluation of the hearing aid, a hearing aid analyzer, calibrated acoustic transducers, sound proof room, etc. These systems and methods for using them are generally not suitable for self-administration by a hearing aid consumer in home settings.
Characterization and verification of a hearing aid are generally conducted by presenting acoustic stimuli (sound) to the microphone of the hearing device, referred to herein generically as a “microphonic” or “acoustic” input. The hearing aid may be worn in the ear (in-situ) during the fitting process, for what is referred to as “real ear” measurements (REM), using an REM instrument. The hearing aid may also need to be placed in a test chamber for characterization by a hearing aid analyzer. The acoustic stimulus used for hearing aid and fitting assessment is generally tonal sound, but may include synthesized speech spectrum noise, or other speech-like signals sometimes referred to as “digital speech.” Real life sounds are generally not employed for determining a hearing aid prescription or for adjustment of the fitting parameters with the user's subjective assessment. Hearing aid consumers are generally asked to return to the dispensing office to make adjustments following real-life listening experiences with the hearing device. When simulated “real life” sounds are employed for hearing aid evaluation, calibration of the real life input sounds at the microphone of the hearing aid is generally required, involving probe tube measurements, or a sound level meter (SLM). Regardless of the particular method used, conventional fitting generally requires clinical settings to employ specialized instruments for administration by trained hearing professionals. Throughout this application, the term “consumer” generally refers to a person being fitted with a hearing device, thus may be interchangeable with any of the terms “user,” “person,” “client,” “hearing impaired,” etc. Furthermore, the term “hearing device” is used herein to refer to all types of hearing enhancement devices, including hearing aids prescribed for hearing impairment and personal sound amplification products (PSAP) generally not requiring a prescription or a medical waiver.
Programmable hearing aids rely on electronic adjustments of electroacoustic settings, referred to herein generally as “fitting parameters.” Similar to hearing assessments and hearing aid characterization, the programming of a hearing aid generally requires specialized instruments and involvement of a hearing professional to deal with a range of complexities related to programming fitting parameters.
Resorting to consumer computing devices for hearing evaluation and fitting, such as personal computers, smartphones and tablet computers, to produce test stimuli is generally problematic for several reasons, including the variability of sound output characteristics with consumer audio components employed therewith. For example internal speakers or external headphones may not be easily calibrated and/or may not meet audio standards of audiometric and hearing aid evaluations, such as total harmonic distortion (THD), accuracy of amplitudes, noise levels, frequency response, and the like.
Furthermore, conventional fitting processes are generally too technical and cumbersome for administration by a non-expert person. For the aforementioned reasons, among others, the fitting process for a programmable hearing device is generally not available to consumers for self-administration at home. A hearing aid dispensing professional is typically required for conducting one or more steps of the fitting process, from hearing evaluation to hearing aid recommendation and selection to prescription and programming of the fitting parameters into the hearing device. This process often requires multiple visits to the dispensing office to incorporate the user's subjective assessment from listening experiences after the initial fitting. As a result, the cost of a professionally dispensed hearing aid can easily reach thousands of dollars, and almost double that for a pair of hearing aids. This expense represents a major barrier to many potential consumers. Even though cost of parts and labor to manufacture a hearing device is generally under $100, the average retail price for a programmable hearing aid is well over $1000, largely due to the cost of fitting by the dispensing professional. In addition to the cost, another obstacle for potential hearing aid customers is the inconvenience of the multiple visits to a dispensing office that are required for hearing aid testing, selection and fitting.